package com.cskaoyan.order.biz.handler;

import com.cskaoyan.mall.commons.exception.BizException;
import com.cskaoyan.order.api.ProductApi;
import com.cskaoyan.order.biz.context.CreateOrderContext;
import com.cskaoyan.order.biz.context.TransHandlerContext;
import com.cskaoyan.order.dal.entitys.Stock;
import com.cskaoyan.order.dal.persistence.StockMapper;
import com.cskaoyan.order.dto.CartProductDto;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import org.springframework.transaction.annotation.Transactional;
import org.springframework.util.CollectionUtils;

import java.util.List;
import java.util.stream.Collectors;

/**
 * @Description: 扣减库存处理器
 **/
@Component
@Slf4j
public class SubStockHandler extends AbstractTransHandler {

    @Autowired
    StockMapper stockMapper;

    @Autowired
    ProductApi productApi;

    @Override
    public boolean isAsync() {
        return false;
    }

    @Override
    @Transactional
    public boolean handle(TransHandlerContext context) {

        CreateOrderContext createOrderContext = (CreateOrderContext)context;
        List<CartProductDto> dtoList = createOrderContext.getCartProductDtoList();
        List<Long> productIds = createOrderContext.getBuyProductIds();
        if (CollectionUtils.isEmpty(productIds)){
            productIds = dtoList.stream().map(u -> u.getProductId()).collect(Collectors.toList());
        }
        productIds.sort(Long::compareTo);

        // 锁定库存
        List<Stock> stockList = stockMapper.findStocksForUpdate(productIds);

        if (CollectionUtils.isEmpty(stockList)){
            throw new BizException("库存未初始化");
        }

        if (stockList.size() != productIds.size()){
            throw new BizException("部分商品库存未初始化！");
        }

        // 扣减库存
        for (CartProductDto cartProductDto : dtoList) {

            Long productId = cartProductDto.getProductId();
            Long productNum = cartProductDto.getProductNum();

            Stock stock = new Stock();
            stock.setItemId(productId);
            stock.setLockCount(productNum.intValue());
            stock.setStockCount(-productNum);

            stockMapper.updateStock(stock);

            // 修改tb_item中的库存(num)数量和售卖数量限制(limit_num)
            productApi.reduceStockNum(productId, productNum);

        }
        return true;
    }
}